The present invention relates to a heat-radiating structure of chip, which applies to flip chip package structures to have better heat-radiating paths. Moreover, the stability of the heat-radiating structure can be enhanced, and local concentration of stress and damage caused by aging and fatigue can be reduced.
As shown in FIGS. 1 and 2, a conventional heat-radiating structure of chip comprises a circuit substrate 1a. A chip 2a of flip chip structure is connected on the circuit substrate 1a. An array of several solder balls 21a are disposed at the bottom face of the chip 2a to form a contact face. Ball sockets 11a are correspondingly disposed at the top face of the circuit substrate 1a so that part of each solder ball 21a can be connected at a corresponding ball socket 11a. A structure for electronic signal transmission with other circuit boards is disposed at the bottom face of the circuit substrate 1a. This structure is a ball grid array 3a in FIG. 1, and can also be a pin grid array. In addition to electronic signal transmission, the ball grid array 3a can also provide a heat-spreading path for the working chip 2a. 
However, along with increase of the operating power of the chip 2a, more heat is generated per unit time so that simply the heat-spreading path of the ball grid array 3a is not sufficient. Therefore, the temperature of the chip 2a itself becomes higher and higher, hence affecting the working performance of the chip or even damaging the chip.
Accordingly, a heat-radiating component 4a is further disposed on the chip 2a. The heat-radiating component 4a comprises a high frame 5a and a heat-radiating plate 6a. The high frame 5a provides support to the heat-radiating plate 6a on the circuit substrate 1a. The heat-radiating plate 6a adheres to the high frame 5a and the surface of the chip 2a through an adhesive 7a (as shown in FIG. 2). The high frame 5a also adheres to the circuit substrate 1a through the adhesive 7a. 
Although the conventional heat-radiating component, provides a good heat-spreading area and a certain degree of protection for the chip, it is of a two-piece design so that more cost is required in assembly steps and time and the use quantity of adhesive.
Besides, due to temperature rise when the chip operates and temperature drop when the chip stops operating, local concentration of stress and aging and fatigue at the adhesive regions will occur because of thermal cycle loading and difference between thermal expansion coefficients of different materials, hence causing local damage to result in falling off of the heat-radiating component from the chip.
Accordingly, the above heat-radiating structures of chip have inconvenience and drawbacks in practical use. The present invention aims to resolve the problems in the prior art.
The primary object of the present invention is to provide a heat-radiating structure of chip having an integrally formed heat-radiating component. The heat-radiating structure of chip can provide a good structural rigidity and stability, decrease thermal stress damage caused by thermal deformation, and reduce local concentration of stress and damage caused by aging and fatigue.
Another object of the present invention is to provide a heat-radiating structure of chip having a separately disposed bearing rack. The bearing rack forms an intermittent structure to avoid positions with a too large local thermal stress. Moreover, the use quantity of adhesive can be reduced, and the requirement in adhesion strength can be lowered. Moreover, gaps of the bearing rack provide flow passages for hot air in the heat-radiating component.
To achieve the above objects, the present invention provides a heat-radiating structure of chip disposed around a flip chip type chip on a circuit substrate. The heat-radiating structure of chip comprises a heat-radiating sheet for conducting out beat of the chip and a bearing rack extended from the heat-radiating sheet. The bearing rack is disposed near sides of the heat-radiating sheet facing the surface of the chip. Moreover, an adhesive is connected between the top face of the chip and the surface of the heat-radiating sheet.
The present invention also provides another heat-radiating structure of chip disposed around a flip chip type chip on a circuit substrate. The heat-radiating structure of chip comprises a heat-radiating sheet for conducting out heat of the chip and a bearing rack extended from the heat-radiating sheet. The bearing rack is disposed near sides of the heat-radiating sheet facing the surface of the chip. The bearing rack is divided into at least two parts. Moreover, an adhesive is connected between the top face of the chip and the surface of the heat-radiating sheet.
The present invention also provides another heat-radiating structure of chip disposed around a flip chip type chip on a circuit substrate. The heat-radiating structure of chip comprises a heat-radiating sheet for conducting out heat of the chip and a bearing rack extended from the heat-radiating sheet. The bearing rack is disposed near sides of the heat-radiating sheet facing the surface of the chip. Each side of the bearing rack is divided into at least two parts, and each side of the bearing rack is not connected to one another. Moreover, an adhesive is connected between the top face of the chip and the surface of the heat-radiating sheet.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing, in which: